1. Field of the Invention
The present invention relates to an optical touch control apparatus, and an adjustable light guide apparatus, and particularly relates to an optical touch control apparatus, and an adjustable light guide apparatus that can change image capturing range.
2. Description of the Prior Art
A mouse utilizing a scrolling ball or a tracking ball is gradually replaced with an optical mouse or an optical touch control apparatus. Such optical mouse or optical touch control apparatus all determine displacement between a detecting surface of an apparatus and an object (ex. a finger or a surface on which a mouse moves).
FIG. 1 illustrates an optical touch control apparatus 100, which is utilized to detect displacement for an object on a detecting surface. FIG. 1(a) is a cross-sectional diagram of the optical touch control apparatus 100, while FIG. 1(b) is a block diagram illustrating circuits, which are inside the optical touch control apparatus and utilized to control the operation of the optical touch control apparatus. The optical touch control apparatus 100 includes an object detecting apparatus 102 (including a detecting surface 103 and a light source 105), an image sensor 107, lens 109, 111, a control unit 113, a storage apparatus 115 and a light source control unit 117. The object detecting apparatus 102 detects an object image of an object. Specifically, the light source 105 is controller by the light source control unit 117 to control the illumination operation thereof to illuminate a finger 101 on the detecting surface 103 to generate an image. Also, the image sensor 107 captures frames in the image. The control unit 113 computes displacement of the finger 101 according to caught frames. Additionally, the control unit 113 also controls data accessing of the storage apparatus 115 and the operation of the light source control unit 117.
The above-mentioned object detecting apparatus can further comprise a light guide plate besides the detecting surface 103 and the light source 105 shown in FIG. 1. As shown in FIG. 2, the object detecting apparatus 202 includes a detecting surface 203, a light source 205 and a light guide plate 207. The light source 2-5 emits light into the light guide plate 207, and then the light guide plate 207 guides the light to the finger 201 on the detecting surface 203 and generates the image according to the reflected light. The image sensor 211 captures the frames via the lens 209.
However, the image capturing range of the above-mentioned object detecting apparatus is fixed. That is, the image capturing range may occupy most part of the detecting surface, even all of the detecting surface. However, a large image capturing range is not always needed. For example, an user may only needs to move up or move down the frame shown on the screen while seeing data on a website, thus only a narrow image capturing range is needed for the move up/move down action. Therefore, if the image capturing range can not be changed, the image sensor will consume power to ineffective image capturing range and the light source must illuminate a larger range, thus power consumption increases.